The difference between this kinds of heavy duty type Polyurethane Casters and the other PU Wheels is the thickness of Polyurethane. DC Casters engineer increase wheel thickness to 75mm, also raise the steel sheet thickness to 12mm. These two improvements make the max. loading capacity arrive 800KGS. For the 6 Inch. 8Inch,10 Inch and 12Inch also get the same level of improvement. Finally, 12Inch Polyurethane Casters can reach up to 2000 Tons Loading Capacity.